VPN client can not connect to the server in Manjaro 20.2

I just installed manjaro 20.2(kernel is 5.9.16-1) with kde desktop environment. I quite like it . but the vpn client is not work ,and I can not connect to my company intranet.

I installed this forticlient from aur (forticlient-vpn) and when try to connect, I see there’s below log in the syslog. it keeps printing pppd|Modem hangup and then |pppd|Connection terminated.|

|1/5/21 7:45 AM|pppd|pppd 2.4.7 started by peter, uid 0|
|---|---|---|
|1/5/21 7:45 AM|kernel|PPP generic driver version 2.4.2|
|1/5/21 7:45 AM|pppd|using channel 1|
|1/5/21 7:45 AM|pppd|Using interface ppp0|
|1/5/21 7:45 AM|pppd|Connect: ppp0 <--> /dev/pts/5|
|1/5/21 7:45 AM|pppd|sent [LCP ConfReq id=0x1 <mru 1024> <magic 0xae4e645f>]|
|1/5/21 7:45 AM|NetworkManager|<info>  [1609803946.2270] manager: (ppp0): new Ppp device (/org/freedesktop/NetworkManager/Devices/4)|
|1/5/21 7:45 AM|pppd|Modem hangup|
|1/5/21 7:45 AM|pppd|Connection terminated.|
|1/5/21 7:45 AM|pppd|Exit.|
|1/5/21 7:45 AM|pppd|pppd 2.4.7 started by peter, uid 0|
|1/5/21 7:45 AM|pppd|using channel 2|
|1/5/21 7:45 AM|pppd|Using interface ppp0|
|1/5/21 7:45 AM|pppd|Connect: ppp0 <--> /dev/pts/5|
|1/5/21 7:45 AM|pppd|sent [LCP ConfReq id=0x1 <mru 1024> <magic 0x30ec7003>]|
|1/5/21 7:45 AM|NetworkManager|<info>  [1609803950.9071] manager: (ppp0): new Ppp device (/org/freedesktop/NetworkManager/Devices/5)|
|1/5/21 7:45 AM|pppd|Modem hangup|
|1/5/21 7:45 AM|pppd|Connection terminated.|
|1/5/21 7:45 AM|pppd|Exit.|
|1/5/21 7:45 AM|pppd|pppd 2.4.7 started by peter, uid 0|
|1/5/21 7:45 AM|pppd|using channel 3|
|1/5/21 7:45 AM|NetworkManager|<info>  [1609803952.8008] manager: (ppp0): new Ppp device (/org/freedesktop/NetworkManager/Devices/6)|
|1/5/21 7:45 AM|pppd|Using interface ppp0|
|1/5/21 7:45 AM|pppd|Connect: ppp0 <--> /dev/pts/5|
|1/5/21 7:45 AM|pppd|sent [LCP ConfReq id=0x1 <mru 1024> <magic 0xef15f5b2>]|
|1/5/21 7:45 AM|pppd|Modem hangup|
|1/5/21 7:45 AM|pppd|Connection terminated.|
|1/5/21 7:45 AM|pppd|Exit.|
|1/5/21 7:45 AM|pppd|pppd 2.4.7 started by peter, uid 0|
|1/5/21 7:45 AM|pppd|using channel 4|
|1/5/21 7:45 AM|pppd|Using interface ppp0|
|1/5/21 7:45 AM|pppd|Connect: ppp0 <--> /dev/pts/5|
|1/5/21 7:45 AM|pppd|sent [LCP ConfReq id=0x1 <mru 1024> <magic 0x2bcc349a>]|
|1/5/21 7:45 AM|NetworkManager|<info>  [1609803954.2170] manager: (ppp0): new Ppp device (/org/freedesktop/NetworkManager/Devices/7)|
|1/5/21 7:45 AM|pppd|Modem hangup|
|1/5/21 7:45 AM|pppd|Connection terminated.|
|1/5/21 7:45 AM|pppd|Exit.|
|1/5/21 7:45 AM|pppd|pppd 2.4.7 started by peter, uid 0|
|1/5/21 7:45 AM|pppd|using channel 5|
|1/5/21 7:45 AM|pppd|Using interface ppp0|
|1/5/21 7:45 AM|pppd|Connect: ppp0 <--> /dev/pts/5|
|1/5/21 7:45 AM|pppd|sent [LCP ConfReq id=0x1 <mru 1024> <magic 0xdaecb01e>]|
|1/5/21 7:45 AM|NetworkManager|<info>  [1609803955.6287] manager: (ppp0): new Ppp device (/org/freedesktop/NetworkManager/Devices/8)|
|1/5/21 7:45 AM|pppd|Modem hangup|
|1/5/21 7:45 AM|pppd|Connection terminated.|
|1/5/21 7:45 AM|pppd|Exit.|

Search engine shows that more people had this issue. Not knowing if they have found any solution.